Heating system



June 29, 1943. R. E. MOORE v2,322,872

HEATING SYSTEM Filed Oct. 8, 1941 4 Sheets-Sheet 1 .Ziz/erzzor: ZOZeTLZZZIOQWa f Ju 29, 1943. R; E. MO RE HEAIING SYSTEM Filed Oct. 8, 1941 4 Sheets-Sheet 2 June 29, 1943. R. E. MOORE HEATING SYSTEM Filed Oct. 8, '1941 4 Sheets-Sheet 4 QZizdnfarr ,j aerZfZU/obr localities where the service water is Patented June 29, 1943 UNITED STATES Pusanerries neariifitsihM Robert n. Moore, Park Ridge, n1. f Application October s, 1941, Serial No. 414,12:

(oust-er 9 Claims.

My invention relates to hot water heatingsystems and more particularly to an arrangement for supplying hotwater to the radiators and hot water for service or domestic use in quantities limited only byboiler or waterheater capacity and in which the boiler is only required to satisfy either one 01 these demands at any one time.

In hot water heating systems which are intermittently and automatically flr'ed by gas or oil, a characteristic hookup includes a main circuit leading to the radiators control valves operated by a circulating pump which is responsive to the demands of a room thermostat and a parallel service water heating circuit through which boiler water flows continuously and th'ermogravitationally and therefore are formed rapidly in the storage tank or the coils of the heater, thus: reducing the rate of heat exchange and lowering the temperature of the water available at the service outlets. This liming condition .is continuouslyv aggravated by recurrent periods of overheating. Problems of the foregoing nature are frequently encountered in apartment, restaurant, garage and hotel heathaving one or more flow at a slow rate when the pump is not operating. 1

It hasbeen recognized thatwhile a system of this type possesses simplicity of arrangementwhich is reflectedin certain installationadvantages, itis objectionable in other respects, name-.- ly, a heating efllciency that is lower than it should be andlonger a and burner under conditions of sustaineddemand "on" periods of the pump by'either the room thermostat or for service waterorboth.

Eur example, ifafter a sustained draw of service water with a consequent reduction in the air across the heating temperature of the boiler water, theroom thermostat should demand heat, there will obviously in supplying adequate heat be a considerable leg I a to the radiators,,l,since the boiler is at "the same time trying to service water. This condition is due tively low initial temperature of the at the instant cold water from to the relaboiler water of demand and alsobecause the met. 'Moreover, dueto the slow movement of.

the boiler water across the hotiwater heating coil during inactive periods of the" pump, the,

exchange of heat is relatively inei'flcient. Further, dimculties arise in installations of the foregoing character due to lack ot c ontrol overthe temperature of the service" water. In certain heated by the boiler water to a temperature in excess of 140 F., deposits of lime and sediment restore the temperature of the.

the radiators is continuously circulated through the boiler and over or through kinds oi demands neither the radiator.

tion of the foregoing is .possibleii boilers larger thanthe ordinaryoversize boilers are used with corresponding sizes of heating coils and hot water, storage tang, Such costs, however, must usually be considered. The;initial-investment required with such a system isnot onlyprohibitive but thefuel costs and heat losses areexcessive and there is an extremely wasteful standby heat loss when there are no demands for radiator and service water. The latter condition is espe-' cially true with boilers that are built for :gas fi n since such boilers are designed with large heating surfaces and relatively small water capaeity. Accordingly. whenthe burner stops due to the sweep of cold surfaces in its passage to the chimney and the temperature of the service waterlikewise falls. I

'It is therefore the principal object of my. invention to 'devise-a,heating system which utilizes a boiler, economical in sizefand fuel: consumption, and so related to the remainder of the i system that copio muantities of hot service water are immediately availablewithin a shorter timjthan is possible with existing equipment and in which hot water for the radiators is furnished more quickly.

A i'urther object is todevise a system which is characterized by a high heating emciency, both space and service water heating, because the a mass of. water ,whose temperature provides the fundamental control is heated by boiler water which has a short circulatory path to and from theboiler so that it may be quickly brohght to thedesired operating temperature.

A further object is to provide a system in which water fromthe boiler is forced through the radiators inqresponse to the demand of the room thermostat forheat only when the temindirectly the service water is above a premaximum. thus insuring an adequate supply of hot service water and also quickly raising the temperature of the water for the radisuch boilers cool rapidly ators when circulation is established, as well as preventing the return of cold water from the radiators to the boiler at times when the temperature of the service water is below the maximum which would otherwise delay the required rise in temperature of the water in the boiler.

A further object is to devise a system having radiator and service water heating portions, passage of water to the radiators being controlled by the demand of a room thermostat for heat and effective only when the temperature of the service water is at a predetermined maximum.

'A further object is to devise a system of the foregoing character in which the same pump forces water through the radiators and also through the service water heater thus increasing the circulatory rate through the heater and facilitating the exchange of heat.

A further object is to provide a heating system of the character indicated in which the flow of water to the radiators is at all times subordinate to the service water being raised to a predetermined temperature.

A further object is to devise a hot water heat- .ing system incorporating a tankless or instantaneous heater for service water in which the flow of water through the heater coil and to the radiatorsnever occurssimultaneously whereby the fullheating capacity of the boiler is applied to either duty.

These and further objects of my invention will beset forth in the following specification, reference being had to the accompanying drawings, and the novel means by which said objects are efiectuated will' be definitely pointed out in the cuit that may be utilized in connection with the;

heating system shown in Fig. l.

Fig. 4 shows a modified system employing a tankless heater in which a draw of service water ing the thermostatic control and valve for determining the flow direction of the boiler water.

Figs. 7 and 8 are sections along lines 'i-| and 8-8 in Figs. 8 and 5, both respectively, showing certain structural details.

Referring to Figs. 1 and 2, the numeral I0 designates agas fired boiler, generally representative of any automatically fired heating unit, which is provided with the usual gas valve II for controlling the flow of the gas to the burner (not shown). A riser l2 extends upwardly from the top of the boiler l0 and communicating therewith is the usual compression tank l3 which traps a portion of the air in the system, providing pressure for the system, and allowing for expansion of the water when heated.

The delivery end of the riser I2 is connected to an intermediate portion of a hollow casing i4 and leading from the lower portion of the casing is a supply pipe i5 which maybe connected to any desired number of radiators lie, the water being circulated back to the boiler It by a return pipe it. For purpose of illustration a one-pipe system is illustrated, althoughv the radiators may be bridgedv between the pipes II and it if desired. In the case of a one-pipe system, the connection of the radiators to the pipe I5 may be effected by fittings oi the type disclosed in Patent No. 1,663,271.

The portion of the system just described may be regarded as the radiator circuit, as distinguished from the service water heating circuit to which reference will now be made.

One end of a pipe I! is connected to the upper portion of the casing i4 so that the pipe 12 is disposed between the pipes l5 and H. The other end of the pipe I! is connected to a heating coil l8 that is submerged in heat exchanging relation within a service water storage tank iii to which cold water is supplied by a pipe 20 and from which hot water is drawn through a pipe 2| to any desired number of service outlets. The tank i9 is preferably disposed at a higher elevation than the boiler. The outlet end of the coil i8 is connected by apipe 2'2 to the return pipe i6 and interposed between the connection of these two pipesand the boiler is a circulating pump 23.

I From the foregoing, it will be understood that boiler water circulation to the radiators is effected through.'the pipes l5 and i6 and to and from the heating coil through the pipes i1 and 22. Instead of passing boiler water through the coil I8, it is considered to be within the range of my invention to employ the equivalent and commonly used arrangement of circulating the boiler water around a coil through which the service water flows.

My invention contemplates that water will be pumped through the radiator circuit only when the service water in the tank I9 is at or exceeds a predetermined temperature, preferably not less than F., and whenever. the temperature of the service water falls below the indicated minimum, flow to the radiator will be interrupted until the temperature of the service water is again brought up to 140 F. notwithstanding that the room thermostat may then be demanding heat. For this purpose, there is interposed in the system a thermostatically controlled valve that is responsive to the temperature of the water in the tank l9 and this valve is illustrated in detail in Fig. 2. l

A pair of spaced valv seats 24 and 25 is symmetrically disposed with reference to the outlet 7 end of the riser l2 and located between the seats is a reciprocable valve 26 that is secured to a valve stem 21 whose upper end is guided in a sleeve 28 provided in the casing 14 while the lower end is substantially pivotally connected to one end of a lever 29 intermediately pivoted in a bushing 30 that is threaded tightly in the casing l4 and extends outwardly of this bushing for connection to the lower end of an operating rod 3 I. In order to prevent loss of water through the bushing 30, a disk 32 is soldered or otherwise leakprooi' secured to the lever 29 and extending between the disk and the bushing is an impervious bellows or flexible sleeve 33. With this arrangement, the

lever 29 can be freely rocked as hereinafter described without loss of liquid fromthe casing M.

The rod 3i extends upwardly through a nipple- 34 that is threadedin the bottom of a cup 35, preferably integrally formed with the casing M and the open end of the cup is closed by a diaphragm 36 whose centralportion is secured to manding heat.

aaaaeva the upper end of therod 3L A helicalspring 31 encircles the rod 3| between the diaphragm and.

nipple 34 and acts to move the diaphragm upwardly when displaced thereirom as hereinafter described. t i A chamber 38 is formed above the diaphragm 38by means of a cover 38 thatis secured to the cup 35, the diaphragm 38 being clamped between the cover and cup. The chamber 38 is filled with a any desired liquid, water or oil being suitable for the purpose. One end of a flexible tube of mall diameter 40 is secured to the cover 39, while the opposite end is connected to a thermostatic casing 4i; which may be cylindrical in shape and which is submerged in the water in the tank iii. The casing 4| may be filled with air atatmospherlc pressure and the parts are so arranged for the particularsystem shown in Fig. 3 that when the temperatureoi the water in the tank reaches,

140 F., the expansion of mesh within the casing 4| applies pressure to the liquid in the chamber 38 which flexes .the diaphragm 38 downwardly to thereby move the-valve 28 into contact with the seat 24, thus preventing flow of boiler water to the coil I8 and permitting the water to flow to the radiators if the room thermostat 42 is then de- However, when the temperature of the waterin the tank I9fa1lsbelow 140 F., the p pressure on the liquid in the chamber 38 is cor-.,

moves the diaphragm 38 upwardly shifting the valve 28 into contact with the seat whereupon respondingly reduced and the spring 31 then the boiler water flows throughthe coil l8. and,

none. can. pass to the radiators; 1 The thermostatic power unit, including. the casing 4i and allied parts, in and, of itself forms no part of the present invention but has been adopted as providingavery efllcient arrangement for determining the direction of flow of the boiler water.

In one installation, the casing was formed as a copper cylinder having-a length of 18 inches and an: out- 8 side diameter of 1 inch. The air was originally introduced into the casing 4| at atmospheric pressureand under test, it was ascertained that a temperature riseof 80 F. of the service water provided an effective push attheend of such rise of about 9 pounds on the lever 29. Other gases than air may be employed and at pressures other than atmospheric. The usual flow control valves "and 44 operable by the pump 23 may beinterposed inthe pipe l5 and in the'pipe l8, respec-' tively, anterior to the connection of the pipe 22 therewith to prevent 'thermogravitational fiow to 28 contacts the the radiators when the valve seat 24. I In order to provide for the automatic control of the system, thereis mounted in the boilera high limit or safety control 45 which is only diagrammatically shown in the drawing; but which it will be understood breaks the electrical circuit presently discussed when the boiler temperature exceeds, for example, 220 F., ,while there is mounted in the storage'tankulii a direct acting aquastat48 that is includedwithin theindicated electrical circuit and which is closed whenever thetemperature of the water in the tank drops below140" F. and opens above this temperature. The room thermostat 42 isalso included in the above circuit and is located ;to radiators. 1 a

A main switch 41 p power line generally indicated by the numeral 48* and leading from the switch is shot wire which i'sconnectedto the control 45.

leads frornthe vcontrol 45 to the room thermostat: 42 and also by means or awire 5l to the aquastat 7 5 A hotwire 50 r be effected by the o 48. The aquastst and room thermostat are also connected bys wire 82, whilea wire 53 connects the wire "with the gas valve and is also connected by a wire 54a to s. motor 84 which drives the pump 23. Ground wires Bland "connect the motor and; gas valve 1 I respectively, with a ground wire 51 which in turn is connected to the switch 41. i

In describing the operation of my improved systemyit will be assumed that the temperature of the; water in the tank I! is below 140 F. Un-

-der these conditions, the aquastat 48 is closed and the pressure in the casing" is such that the springll has flexed the'diaphragm 38 upwardly to move the valve 28 intocontact with the seat 25. The circuit through the motor 54 and gas valve ll being completedithe boiler is subjected to heatand "hot water is continuously circulated by the pump 23 through waterin thetankl8; 5*]

This situation continues notwithstanding that the room thermostat 42 the temperature of the service water has reached 140. F., when the aquastat 48'opens. If at the instant of opening, the roomethermostat 42 de mands heat,.the circuit through the motor 54, and gas valve H is completed and since the thermopower unit shown in Fig. 2 becomes operable at the interrupting temperature of the aquastat 43, the pressure set uprin the casin 4| flexes the diaphragm 38 downwardly thus moving the valve 28 into, contactwith the valve" seat 24 and per,

mitting all boiler water to be pumped to the,

for service water sufliciently heavy to cause the water temperature in the tank l9 to drop below 140 F., the valve 28 is immediately moved downward to prevent flow to the radiators and to cause all water to be pumped through the coil between-thiscircuit and that illustrated in Fig. 1 residesi n the use of a three-wire aquastat 58 which is submerged in the tank l8. In this system, theline wires 48 are connected through the switch 41 to the remainder of the circuit and in the latter a hot wire 59 connects the switch to one terminaljoi the high limit control 45; while the otherfte'rminal is connected by a wire to one terminal 8| of the aquastat 58. 1 The common terminal 82 of the aquastatt is connected by a i Ihw're 3 h um mo r 4. rov'ides a connection to a 1 6 to t e p p to 5 and also through a wire 84 to the gas valve H. The motor 54 and valve II are inturn connected by ground wires 85 and 88 toa common groundwire 8lleading' back to the main switch 41. The room therniostat 42 isc'onnected bya'wire 88 tothe wire 88 may demand heat, until l8 dueto the closing of the aquastat 48. Circu lation through the radiators is resumed when thermostat is, then i terminals 62 and m sc that when the room thermostat 42 demands heat, its closure results in an opening of the gas valve II and operating the pump motor 54 to thereby cause a forced circulation of water through the radiators.

'It will be understood that the remainder of the system shown diagrammatically in Fig. 3 is identical with that illustrated in Fig. 1. I

In Figs. 4 to 8, inclusive, there is illustrated a modified heating system employing a tankless or instantaneous service water heater in which the several parts are arranged so that draws of service water and a flow ofhot water to the radiators can never occur simultaneouslyr In this modification, the numeral I designates a gas fired boiler having the usual gas valve II for supplying fuel to the boiler. In this particular instance, the boiler is indicated as being of that type wherein the water flows downwardly across the heating surfaces of the boiler as distinguished from the upward flow illustrated in Fig. 1.

Accordingly, from the lower portion of the boiler extends a. supply pipe I2 whose delivery end is-connected to a thermostatically controlled valve structure generally. indicated by the numeral 13 in Fig. 4. The internal construction of this unit, will be hereinafter described, but for the present, it will be understood that it contains devices for controlling the flow direction of hot water issuing from the boiler 10 through the pipe 12. This water may be either directed through a pipe 14 into a service water heating tank I5 and thence through a return pipe I8 to the boiler III, the pipe 16 including'the usual circulating pump 11, or the hot water may be directed through the radiator supply pipe I8 to, one or' more radiators 19, which may be connected to the system as described for the system illustrated in Fig. 1, and thence by a return pipe 80 which connects with the return pipe I6 on the inlet side of the pump I1. Preferably, the pipes I8 and 80 are provided with flow control valves 8|v and 82 which open only when the; pump is: operating and the valve structure13 is conditioned to pass water through the pipe 18 and are closed at all other times. As is well understood in. the art, these valves perform another function during the summer season in that they prevent thermogravitational flow of hot boilerwater through the radiators.

Cold water is supplied by a pipe 83 which may be connected to any source of water, such as a city main, and this cold supply is passed through the valve structure I3 in order to exercise a certain control on the operation of the system as hereinafter described and thence through the 5 to 8,'inclusive, to which reference will now be made.. v Itcomprises a tubular member 81 (see Fig. 5) whose upper end is connected to an elongated valve housing 88 having spaced transverse walls 89 and 90 which divide the interior of the housing into an intermediate chamber 9| and upper and lower chambers 92 and 93, respectively. Valve seats 94 an 95 are mounted in the walls 89 and 90, respectively, in spaced and opposed relation and these seats are engaged by a reciprocable valve 96 that is securedto a stem 91, the upperend of the stem being guided in a sleeve 98 secured to the upper end of the housing 88.

As indicated in Fig. 5, the delivery end of the supply pipe 12 from the boiler is connected to the lower end of the member 81 so that hot boiler water courses upwardly through the member 81 and thence into the chamber 9| where the direction of the water, either into the chamber 92 or the chamber 93, is controlled by the position of the valve 96. For purpose of easy illustration, the valve 96 is shown in an intermediate position between the seats 94 and 95, but it will be understood that it normally occupies a position in contact with either one of the seats depending upon conditions occurring in other parts of the system. The inlet end of the pipe I4 communicates with the chamber 92, while the inlet end of the pipe I8 communicates with the chamber 93.

The lower end of thevalve stem 91 i pivotally connected to one end of a lever 99 which is intermediately. pivoted in a nipple I00 that is wardly through a bushing I04 mounted in the bottom of a cup I05 whose open end is closed by a diaphragm I06. The periphery of the diaphragm is clamped against the cup I05 by a cover I01 formed as an inverted of the rod I03 is secured to the diaphragm and interposed between the diaphragm and bushing I04 is a helical spring I08 which serves to move cup. The upper end the diaphragm I06 upwardly when downwardly displaced as hereinafter. described. The unit comprising the cup I05'and cover I01 may be I supported from the housing 88 by a bracket I09.

pipe 84 to a service water heating coil 85 which is immersed in the water in the tank I5. The delivery end of the coil 85 is connected by a pipe 86 to any desired number of service outlets. As presently described, the tank I5 contains water substantially at boiler temperature whenever the valve structure I3 is conditionedto pass boiler water through the pipe I4.

The cover I01 may be filled with water or any desired liquid and one end of a small tube I I0, the internal diameter of order of 1 of an inch, is connected to the interior of the cover I01, while the opposite end is mounted in a cup II I that is secured to the lower end of the member 81 (see Fig. 5). The lower end of a casing H2 is supported by the cup III and may contain air or any gaseous medium which communicates with the water in the casing through the tube H0. The casing H2 is preferably coaxial with the member 87 and it extends for substantially the length thereof. Also coaxial with the member 81 and disposed therebetween and the casing H2 is a tube II3 whose l lower end is rested on a shoulder provided in the The thermostatically controlled valve struccup II! and whose upper end is closed, the

which may be of the v assasva ilpcr ends of the casing H2 and tube Ill bein spaced from each other as indicated in- Fig. 5. p

A pair of diametrically arranged baffles Illill are disposed between the casing ill and tube III with their lower ends restlngon the bottom wall of the cup .I ii and the upper ends terminating close to the upper endof the casing III.

This construction provides a pair of passages I I! and H between the casing H2 and the tube H3 so that cold water flowing through the pipe .3

is caused to traverse upwardly and downwardly f the full length of the casing H2 before passing :into the pipe 84 for delivery to the coil I; {this arrangement insures that when a fauo't'ids opened, the col wa'ter flows along the surface of the casing H2 and exercises an almost instantaneous effect .on' the gas in the casing to thereby; insure a prompt shifting of the valve 96 as hereinafter described. V

The lever 99 extends beyond its pivotal connection with the rod i0! into operative relation .to electric switches H1 and H8 which are located 'in opposed relation on opposite sides ofthe lever 89 and which, respectively, are provided with fingers H9 and IN which are engaged by the rocking movement of the lever to i close the switches. internal-construction of these switches form no part of the present ln-" vention and have not been illustrated in detail.

but it be understood that the switch H1 is close when the finger i II is moved upwardLv and theswitch III is closed when the finger i2! i pushed downwardly. The switches may be coin-v veniently carried by an arm ill from The switches i n and in form part of an electrical circuit which will now bedescribed. Re-

rflns to Fig. 4, the numeral m d J 1 a power line which is connected to the remainder of the circuit by a main switch I23." From the long as a faucet is open so thatthe full capacity continuously circulated downwardly through the boiler and upwardly through the pipe I2, the an- 1 nular passage I38 surrounding the tube 3 and thence through the pipe ll, tank and return pipe I! to the boiler. This condition persists as of the boiler III is directed to satisfying the de- I mand for hot service water.

when thefaucet is closed, cold water no longer flows through the passages III and H8 and the water then contained in these passages is heated p by the hot water in the passage I" which is substantially at boiler temperature. The heating of the water in the passages III and Ill raises the temperature of the air in the casing mi so that the diaphragm I" is moved downwardly. thus rocking the lever 89 in a counterclockwise direction and opening the switch ill, thus breaking the circuit to the pump motor and gas valve. The last noted rocking of the lever 09 engages the valve with seat 8|, whereupon the-device is conditioned to supply hot water to the radiators 'whenever'the room thermostat I33 demands heat, and also engages the pin I20 and closes the switch "8. Therefore, when the thermostat I33 demands heat, the electric circuit is again closed through the pump motor I21 and gas valve Ii so that the full capacity of the boiler 10 is utilized to supply heat to the radiators. If at any time latter switch leads a hot wire I to one ter minal of the switch H1, and from the other terminal of this switch leads a hot wire Ill to a high limit or safety control. ill conveniently mounted in the supply line 12, the control I20 possessing the same characteristics asthecon'trol 48' in Fig. l. A hot wire I21. connects the control I20 with one terminal 0! a motor Ill which is drivably connected to the pump 11 and a hot wire I29 connects the wire I" withv the gasyllvo H.

-A ground wire I10 connectsthe gas valve with the main switch I! and a similar wire I con nects the pump motor Ill with the wire I.

Awire ll! connects the wire I witharcoin' thermostat I positioned to be affected by the radiator It and a wire I connects the thermostat with one terminal of the switch ill. The

other terminal'of the switch is connected by the wire In to thewirem. i

In describing the'operltion of this system. it

-willbe assumed that one of the service outlets (not shown) is open so that cold water is flowing through the passages Ill and ill to the heating coil II. Under these conditions, the cold water chills the air or gas within the casing ll! sumciently to enable the spring I tomove the diaphragm Ill upwardly and cause the valve" to engage the seat 5, thereby diverting water from the boiler II into the pipe 14 and thence through the tank II.

This clockwise rocking of the lever II, as viewed in Fig. 6, engages the finger Ill and closes the switch lll which completes the electric circuit through the motor in and the gas valve 1i Acx operated in the usual manner, 1. e., by setting the during the period when the radiators are being supplied with hot water, a faucet should open,- the ensuing flow of cold water through the possages Band II. chills theairinthe casing H2,

whereupon the lever t! is-rocked in a clockwise direction to engage'the valve it with the seat I! h and close the switch I"; Thefirst noted operation of heating the service water will then be re- I have ascertained that after all the faucets 0 have been closed, the valve it is shifted from a position the seat to one 'in contact with the seat 04 in approximately five seconds so Y that even though there should be a demand by the room thermostat III immediatelyafter the closing of the faucets, only a very short time is to condition the system for radiator supply. From a temperature standpoint, a variation of 26'1". in thetemperature ofthegas in'the cas- 1 "ing lllsis sufficient to shift the valve I! from one position to anotherifthe pump isnot operating.

Ordinarily, water from a city main would enter the passage Ill-at approiimately 80 Rand since the water in ,the boiler is never below I. a surplus of themiopower is available toeffect each operation of the valve II.

During summer operation, when hot water is not desired in the radiators, the systemmay be thermostat ill to a point such that itcan never demand heat. Hence regardless of the closing of the switch lllthe pump motor I" will not function because the thermostat III is then open, while the valves II and I! prevent thennogravitational flow to the radiators during times when the valve I is in contact withthe seat .4.

I claim: p

1. In a hot water heating system, the combination of a boiler, a radiator circuit. a service water heating circuit, the circuits communicating with the boiler,

cordingly, the boiler III is fired and all water is 76 vll tbelow a changinl relation 7 means common to both circuits and responsive to the temperature of the service water for directing the now or boiler water through the service cirpredetermined temperature of the a service water container in heat esto the service circuit, andradiator circuit and thermostatic means responsive to the temperature of the service water and operable to actuate the valve mean to direct the boiler water through the service circuit below a predetermined j respectively, whereby the pump operates in retemperature of the service water and through the radiator circuit above said temperature.

3. In a hot water heatingsystem, the combination 01' a boiler, a radiator circuit and a service water heating circuit each communicating with the boiler, a service water container in heat exchanging relation to the service circuit, a reciprocable valve common to both circuits and shiftable between positions directing the flow to one circuit while denying flow to the other, and means responsive to the temperature or the service water foractuating the valve-to direct the boiler water through the service circuit below a predetermined temperature of the service water and through the radiator circuit at or above said temperature.

4. In a hot water heating system, the combination of a boiler, a radiator circuit and a service waterheating circuit each communicating with the boiler, a service water container in heat er:-

changing relation to the service circuit, a reciprocable valve common to both circuits and shiftable between positions directing how. to one circuit while denying, flow to the} other, and thermostatic means immersed in the service water and lever connected tothe valve for moving the same to admit boiler water only to the service circuit below a predetermined temperature of the service water and only to the radiator circuit at or above the said temperature. a

5. In a hot water heating system, the combination of a boiler, a radiator circuit and a service aquastat, and valve mean for directing boiler,

water to one circuit or the other.

6. In a hot water heating system,'the combination of a boiler, a radiating circuit and a service water heating circuit each communicating with the boiler, a service water container in heat exchanging relation to the service circuit, a, room thermostat positioned to be, affected by the radiator circuit, an aquastat responsiv to the temperature of the service water, a circulating pump common to both circuits, electrical connections between the pump and thermostat and aquastat,

sponse to the demand of the thermostat or aquastat, valve means for directing boiler water to one I circuit or the other, and thermostatic mean responsive to the temperature 01' the service water for actuating the valve means to direct the boiler water through the service circuit below a predetermined temperature of the'service water and through the 'radiatorcircuit above said temperature.

7. In a hot water heating system having a boiler and a radiator circuit and a service water heating circuit, each communicating with the boiler, a valve common to both circuits, and thermostatic means responsive to the temperature of the service water for actuating the valve to direct the. boiler water only to the service circuit below a predetermined temperature 01' the service water and only to the radiator circuit above said temper'ature. V

8. In a hot water heating system, the combination of a boiler, aradiator circuit, a service water water heating circuit each communicating with the boiler, aservice water container in heat ex-' changing relation to the service. circuit, a room thermostat positioned to be affected by the radiator circuit, an aquastat responsiveto the tem-v perature of the service water, a circulating pump common to both circuits, electrical connections between the pump and thermostat'and aquastat, respectively, whereby the'pump operates in response to thedemand oi. the thermostat or the heating circuit, th circuits communicating with the boiler, a service water container in heat exchanging relation to the service circuit and means responsive to the temperature 01' the service water for directing the flow of boiler water through the service circuit below a predetermined tempera- 'ture of the service water and through the radiator circuit above said temperature.

9. In a hot water heating system having a boiler and a radiator circuit and a service-water heating circuit each communicating with the boiler, valve meansior controlling flow through both circuits, and thermostatic means responsive 'to the temperature of the service water for actuating the valve mea'nsto direct the boiler water only to the service circuit below a predetermined temperature of the service water and only to the radiator circuit above said temperature.

. ROBERT E. MOORE. 

